[Anomalous origin of the left coronary artery at the pulmonary trunk and its relationship with other primary coronary anomalies: experimental study].

The origin and course of the coronary arteries were studied in 1,436 Syrian hamsters belonging to 10 breeding colonies subjected to high endogamous pressure by mating either animals of the same litter or first cousins. The study was carried out using a corrosion casting technique. A left coronary artery originating from the pulmonary trunk was found in 48 specimens of the series. In all cases anastomoses had developed between the right and left coronary systems. Moreover, five types of minor primary anomalies of the coronary arteries occurred in 144 hamsters. These findings agree with the morphogenetic hypothesis that each of the aortic and pulmonary sinuses has the potential to develop coronary arteries. Familial recurrence risks for coronary arterial anomalies were estimated taking into account the sex and the inbreeding coefficient of the probands carrying a left coronary artery from the pulmonary trunk. The recurrence risks increase as the inbreeding level increases, this suggesting that the whole primary coronary anomalies are a phenotypic set subordinated to a complex mode of inheritance. Therefore, an echocardiographic study of the first degree relatives of patients with coronary arterial anomalies is advisable to diagnose clinically silent coronary malformations.